Problem: Simplify the following expression: ${3(1-7t)-(-t+2)}$
Distribute the ${3}$ into the first set of parentheses: $ {3(}\gray{1-7t}{)} - (-t+2) $ $ {3-21t} - (-t+2) $ The minus sign in front of the parentheses means we multiply each term inside the parentheses by ${-1}$ $ 3-21t {-1(}\gray{-t+2}{)} $ $ 3-21t + {t-2} $ Rewrite the expression to group the ${t}$ terms and numeric terms: $ {-21t + t} + {3 - 2}$ Combine the ${t}$ terms: $ {-20t} + {3 - 2}$ Combine the numeric terms: $ {-20t} + {1}$ The simplified expression is $-20t+1$